Despite the official announcement of BlackBerry OS 7.1 being available to all carriers, there have been a few hold-outs not willing to go ahead and get the OS out to their customers as soon as possible. T-Mobile was among them until not long ago. If you go ahead and check for system updates on your BlackBerry Bold 9900 right now, you should find OS 188.8.131.52 is readily available for download. Get to it and drop by the forums to let us know how the update went. If you're not seeing it yet, sit tight -- it should be along shortly, the interwebs are magical like that.